AXPZ20 KNHC 232210
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2205 UTC Tue Oct 23 2018
Tropical Weather Discussion for the eastern Pacific Ocean from
the Equator to 32N, east of 140W. The following information is
based on satellite imagery, weather observations, radar, and
Based on 1800 UTC surface analysis and satellite imagery through
Hurricane Willa is centered near 22.2N 106.4W at 2100 UTC moving
NNE at 9 kt. Estimated minimum central pressure is 965 mb.
Maximum sustained wind speed is 105 kt with gusts to 130 kt.
Numerous strong convection is currently observed within 60 nm
across the SE and 90 nm across the NW semicircles, surrounded by
scattered moderate to strong convection in bands within 180 nm
NE and 120 nm SW of the center. Willa has moved across the
northern islands of Las Tres Marias in the past few hours where
a wind gust to 110 kt was reported at the Isla Maria Madre
airport. Heavy rainfall has increased across the coastal zones
from Jalisco to southern Sinaloa this afternoon and will
increase in intensity and coverage along the Pacific coasts of
mainland Mexico from the Guadalajara to north of the Mazatlan
area through this evening as Willa tracks NE and moves inland.
Large swells generated by Willa will continue to impact the
mainland Mexican coast and the southern Gulf of California
between 102W and 108W through tonight, and will produce very
large and powerful surf and life-threatening rip current
conditions. Please refer to local forecasts from the
Meteorological Service of Mexico for specific information on
heavy rainfall and flash flood potential from Willa. Refer to
the latest NHC forecast/advisory under AWIPS/WMO headers
MIATCMEP4/WTPZ24 KNHC for additional details.
Post-Tropical Cyclone Vicente moved northward and inland this
morning across Michoacan and has since dissipated into an
elongated area of low pressure. The remnants has since moved
northward across the area mountains and greatly disrupted the
circulation of this small storm. Residual moisture is expected
to accompany the broader circulation of Willa across central
Mexico during the next 48 hours. Please refer to local forecasts
from the Meteorological Service of Mexico for specific
information on heavy rainfall and flash flood potential from
Vicente and Willa. Refer to the latest NHC forecast/ advisory
under AWIPS/WMO headers MIATCMEP3/WTPZ23 KNHC for additional
A tropical wave is analyzed N of 06N along 93W with scattered
moderate isolated strong convection flaring S of 10N within 150
nm of the monsoon trough.
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
The monsoon trough extends from 09.5N73W TO 09.5N85W TO
06.5N107W, where it breaks, then resumes SW of Willa near
15N106W TO low pres near 12.5N116W TO 10N123W, where it then
transition to ITCZ, which then continues W-NW to beyond 09N140W.
Widely scattered moderate isolated strong convection is observed
within 120 nm N and 150 nm S of the trough between 78W and 104W,
and within 120 nm S of the trough between 106W and 114W.
Scattered moderate to strong convection is from 06N to 10.5N
between 135W and 141W.
OFFSHORE WATERS WITHIN 250 NM OF MEXICO...
See the Special Features paragraph for details on Tropical
Cyclones Vicente and Willa.
W of the Baja california Peninsula...Weak high pressure remains
centered across the far NW waters and is producing moderate to
locally fresh NW flow across the offshore waters, and expected
to persist through early Wed when the pressure gradient will
begin to relax. Large southerly swell from Hurricane Willa will
continue to propagate northward through the waters W of Baja
reaching beyond 30N Wed while NW swell also begins to propagate
into the waters N of 27N, yielding seas of 6 to 8 ft. Seas
should subside to less than 8 ft by late Wed afternoon.
Gulf of California...Fresh to locally strong N to NW winds, and
seas 8 to 12 ft are expected S of 25.5N through late tonight as
Willa passes S of the gulf entrance. Seas of 3 to 5 ft are
possible across the gulf waters S of 25N through the rest of the
Gulf of Tehuantepec...Fresh northerly flow is expected through
OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND
WITHIN 750 NM OF ECUADOR...
Gulf of Papagayo...Pulses of fresh NE flow are forecast through
Light northerly winds and 4 to 7 ft seas are forecast elsewhere
N of the monsoon trough, while moderate to locally fresh
southwesterly monsoonal flow, with 5 to 7 ft seas, are forecast
S of the monsoon trough through the rest of the week.
REMAINDER OF THE AREA...
Refer to the Special Features paragraph above for details on
Tropical Cyclone Willa.
A 1008 mb low near 12.5N116W will drift NW then W over the next
several days with fresh NE flow developing across the NW
semicircle, as it moves south of the ridge to the NW. Seas of 6
to 9 ft seas are expected within 180 nm of the low.
A 1022 mb surface high will meander near 27N138W through Wed
then begin to drift NE ahead of a strong frontal system that
will approach but not reach the far NW waters. An area of
locally strong NE trades and 7 to 9 ft seas will persist across
the tropical waters from 10N to 17N W of 134W for the next few
days. Large NW swell in the form of 7 to 9 ft seas, will reach
30N140W tonight and reach from 32N130W to 20N140W on Wed night
and from 32N120W to 10N135W on Thu night.